Conventionally, as a carrier for carrying a catalyst for purifying an exhaust gas exhausted from an engine of an automobile or the like, a ceramic honeycomb structure (honeycomb structure) having partition walls for defining and forming a plurality of cells extending from one end face to the other end face is used. This honeycomb structure is produced by drying and firing a honeycomb formed body made of a kneaded material containing a ceramic raw material. Then, this honeycomb formed body is obtained by continuously extruding the kneaded material so as to have a honeycomb shape while sequentially cutting the same to an appropriate length.
As a method of sequentially cutting the honeycomb formed body having a honeycomb shape continuously extruded into an appropriate length, a cutting method of a honeycomb formed body by using a thin steel wire (hereinafter referred to simply as a “steel wire”) is generally used. When this steel wire is used, in an initial stage in which this steel wire cuts into the honeycomb formed body, deformation of the honeycomb formed body occurs, and a degree of this deformation is large. Thus, a cutting method that, at a portion in the honeycomb formed body where cutting is to be started, a cut line is made by a knife-shape tool in advance in a direction orthogonal to a direction in which the cell extends, and the steel wire is made to enter this cut line and to cut the honeycomb formed body (see Patent Literature 1, for example) is used in some cases. A method of cutting while vibrating the steel wire in a length direction of the steel wire is also known (see Patent Literature 2, for example).